1. Field of the Invention
The present invention relates to memory devices based on phase change based memory materials, including chalcogenide based materials and other programmable resistance materials, and methods for manufacturing such devices.
2. Description of Related Art
In general, system-on-chip (SOC) technology is the integration of multiple subsystems of an electronic system within a single integrated circuit, and may contain digital, analog, mixed-signal, and radio-frequency functions. The various types of subsystems that may be integrated within the integrated circuit include microprocessor and microcontroller cores, digital signal processors (DSPs), configurable logic units, memory blocks, timing sources, external interfaces, and power management circuits, among others. An SOC consists of both the hardware described above, as well as the software that controls the subsystems. The term “system-on-a-chip” may be used to describe complex application specific integrated circuits (ASIC), where many functions previously achieved by combining multiple integrated circuits on a board are now provided by one single integrated circuit. This level of integration greatly reduces the size and power consumption of the system, while generally also reducing manufacturing costs.
In order to fulfill the memory performance requirements for the various functions of the SOC, different types of memory circuits serving different purposes are typically embedded at various locations in the integrated circuit for memory applications such as random access memory (RAM), flash memory, and read only memory (ROM). However, integration of different types of memory devices for the various memory applications in an SOC can be difficult and result in highly complex designs and manufacturing processes.
It is therefore desirable to provide memory on a single integrated circuit addressing different memory performance requirements such as those demanded of the various functions of SOCs, while also addressing the issue of design integration. It is also desirable to provide methods for manufacturing such devices.